1. Field of the Invention
The present invention relates to a method for initiating an operation for dressing a grinding wheel in conformity with its degree of bluntness, with said grinding wheel being infed towards the workpiece that is to be machined thereby. The present invention also relates to an apparatus for carrying out a method of this type.
2. Description of the Prior Art
In program-controlled grinding machines, it is known to move the grinding wheel towards the workpiece to be machined, and to then carry out grinding. During the machining process, the material removed from the workpiece is measured by a measuring device on a multi-range absolute head, and the infeed distance of the grinding wheel is measured by a distance measuring system. It is possible to calculate from the measurement data when the machining of the workpiece is finished and when the machining operation can be discontinued. Since the grinding wheel is subject essentially to bluntness, that is in effect subject to a reduction in the cutting capacity, due to clogging with particles of dirt and the like, from time to time the wheel must be dressed. Normally the dressing operation is carried out after a predetermined number of machining operations or after a predetermined number of workpieces. In order to ensure that the grinding wheel does not become too blunt before the next dressing operation, the dressing operations are carried out at relatively short intervals. Consequently, the grinding wheel is not utilized in an optimum manner, because the actual bluntness of the grinding wheel is not taken into consideration. The grinding wheel is dressed when the abrasive grains are not yet blunt to the optimum degree; in other words, further machining operations could have been carried out before the dressing operation.
It is an object of the present invention to design the method and apparatus of the aforementioned general type in such a way that the bluntness of the grinding wheel can be determined in a simple manner during machining, so that the grinding wheel can be dressed with optimum conformation to the degree of bluntness.